Tomato Seedlings

I have container grown seedlings in one container whose growing points have yellowed. Other containers are unaffected. Is this a nutrient problem? Could it be due to over watering and/or poor drainage?

If the soil feels overly moist, then it could definitely be a watering/drainage issue. If moisture doesn't seem to be the problem, look to the soil. A soil test can help determine what, if any, nutrients are lacking but the plant may be in need of some nitrogen fertilizer (1/2 strength).